allow mixfix syntax for fixes within a proof body -- should now work thanks to fully authentic syntax;
allow mixfix syntax for fixes within a proof body -- should now work thanks to fully authentic syntax;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle